RAM is 5 to 50 times more latent than cache. SSD is ~1000 times slower than RAM. And a spinning HDD is I think ~100 times slower than an SSD.
If your database fits in RAM you’re likely in a happy place. If your DB is so massive it needs to spill to disk you wind up with a mountain of complexity. Multiple machines, sharding, hot/cold etc.
The point of the article is “modern servers have a lot of RAM and you might be able to delete a lot of complexity if you throw money at a server with 4 terabytes of RAM. This option is more practical than you might have realized!”
Latency (hand wavey) L1: 1 ns L2: 2.5 ns L3: 10 ns RAM: 50 ns SSD: 50,000 ns / 50 us
Those are very approximate and specifics vary.
RAM is 5 to 50 times more latent than cache. SSD is ~1000 times slower than RAM. And a spinning HDD is I think ~100 times slower than an SSD.
If your database fits in RAM you’re likely in a happy place. If your DB is so massive it needs to spill to disk you wind up with a mountain of complexity. Multiple machines, sharding, hot/cold etc.
The point of the article is “modern servers have a lot of RAM and you might be able to delete a lot of complexity if you throw money at a server with 4 terabytes of RAM. This option is more practical than you might have realized!”